Idiopathic nephrotic syndromes due to primary glomerular diseases include the minimal change nephrotic syndrome (MCNS), the focal segmental glomerulosclerosis (FGS), the membranous nephropathy (MN), and the membranoproliferative glomerulonephritis (MPGN). Patients with these diseases fall into hypoproteinemia due to the loss of substantial amounts of protein in the urine during the nephrotic stage, and in order to compensate for the loss, protein synthesis is accelerated in the liver.
The four disease types above are finally diagnosed by taking a sample of the kidney (renal biopsy), and testing the sample with a light microscope and an electron microscope, and also testing the sample through the immunofluorescent antibody method. This diagnostic process is a large burden on the patient and requires time and labor for the histological examination.
Therefore, there has been a demand for a diagnosis method for the nephrotic syndromes by using blood serum or urine, which are relatively easily available. The present invention aims at providing a new diagnosis method. Through this method, the patient can be relieved of the biopsy. At the same time, this method enables the distinction between the MCNS and the FGS, in which the clinical feature is similar to MCNS.